A risk factor is anything that increases a person’s chance of developing a certain condition or disease, such as cancer. In adults, lifestyle and environmental factors (such as smoking or exposure to certain chemicals) can be significant risk factors for developing certain types of cancer. In children, very few risk factors have been identified that increase the chance of developing cancer. For most children with cancer, the underlying cause is unknown.
Even if your child has a risk factor, it does not mean they will develop cancer. Many children with a risk factor will never develop cancer, while others with cancer may have had no known risk factors. Even if a child with a risk factor develops cancer, it is usually hard to know how much that risk factor contributed to the development of their disease.
The causes of non-Hodgkin lymphoma are not well understood, but factors associated with a higher chance of developing non-Hodgkin lymphoma include the following:
Certain genetic disorders that affect the immune system are associated with a higher chance of developing non-Hodgkin lymphoma. These include:
- Wiskott–Aldrich syndrome
- severe combined immunodeficiency syndrome (SCID)
- common variable immunodeficiency
- Bloom syndrome
- X-linked lymphoproliferative syndrome.
If your child is diagnosed with one of these genetic conditions, they will need specific follow-up. The health care team will advise which ongoing tests your child will need.
Cancers in children that are linked to genetic conditions may also affect the risk for other family members. Speak to your child's treatment team to see whether genetic counselling is recommended for you or your family.
Exposure to radiation
Children who are exposed to radiation, or who were exposed to X-rays before they were born, have a slightly higher chance of developing non-Hodgkin lymphoma. Children who have previously had radiation therapy (radiotherapy) to treat cancer also have a slightly higher chance of developing non-Hodgkin lymphoma later in life.
Certain virus infections
People who have been infected with Epstein–Barr virus (also called glandular fever, infectious mononucleosis or 'mono') have a higher chance of developing non-Hodgkin lymphoma, especially Burkitt lymphoma. This risk is higher in children who have had an organ transplant and are receiving medicines that weaken their immune system.
People who are HIV-positive also have a higher chance of developing non-Hodgkin lymphoma.
Non-Hodgkin lymphoma is more common in boys than in girls.